All processes are batch processes to some degree. Even
in continuous process plants, processing units will
need to be shut down at some point and then restarted to resume
production. And whether performing unit startups or
shutdowns (planned or unplanned) or making grade changes or
production rate changes; switching feedstocks; or even doing maintenance work, plant personnel
must perform specific procedures correctly and in the correct
order to ensure smooth plant operation, worker safety and environmental compliance.